This time of year, there’s usually no place in America
that’s hotter than the desert Southwest. The region is known for its striking
red sandstone formations, deep canyons, and ancient ruins. While the desert may
seem like a barren wasteland to the casual observer, it is full of life. If you
know where to look. The critters of the desert have evolved with special
adaptations that allow them to survive in a harsh environment. Let’s have a
look at some.
Extreme heat and scarce water are two hardships of the
desert. Because of the second problem, sweating is an impractical solution to
the first problem. As a workaround, the jackrabbit has large
ears which are full of blood vessels. The blood vessels bring warmer blood away
from the body core to cool. The large surface area of the ears also helps the
cooling process (National Geographic).
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| Black-tailed jack rabbit (NPS) |
The kangaroo rat has adapted to life without
beverages. It can go an extended period without water, absorbing what it needs
from its plant-based diet. Too keep cool, it lives underground and is
nocturnal (Arizona-Sonora Desert Museum).
The various cactus species have evolved to avoid water
loss. All plants lose water through their leaves in a process called
transpiration. Cactus plants minimize the loss by having long, thin needles in
place of the leaves we’re familiar with on trees and other leafy plants. They
also have an extensive root system for maximizing water collection potential
and a wide, hollow stem for water storage (BBC).
Other desert plants have adapted as well. Shrubs and
non-woody flowers survive by growing deep roots that can reach down into the
water table. They have hardy seeds that can last for years before germinating.
When the rare shower falls, these plants simultaneously burst to life in a
brief but spectacular desert bloom (Science News for Kids).
The Great Basin spadefoot toad has a cool adaptation
for surviving in the desert. They burrow underground and remain in a state of
suspended animation for years until rainfall brings it to the surface for
mating and feeding. Mating pairs will lay and fertilize eggs anywhere water
collects, then the race is on for the eggs to hatch and tadpoles to develop
before the water evaporates. The tadpoles are cannibalistic, which might be an
incentive to hurry up and grow (The Nature Conservancy).
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| Great Basin spadefoot toad (Idaho Fish and Game) |
You probably don’t think of shrimp living in the
desert. The fairy shrimp’s habitat is ephemeral (seasonal) pools that form in
depressions in rock. They are tough little buggers, able to withstand extreme
heat. Their eggs can survive desiccation for decades, using sugars instead of
water inside the egg. The eggs can remain in place until rain activates it and
it hatches, or they can be carried on the wind to a new location and hatch
there when rain comes (National Park Service).
Next time you happen to be in the desert, look around for these and other fascinating critters. The desert is alive, if you look hard enough to see the life all around you.
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